The prior art contemplates that chronic wounds may be treated by providing a vacuum in the space above the wound to promote healing.
A number of prior art references teach the value of the vacuum bandage or the provision of the vacuum in the space above the surface of a chronic wound. Several Russian language articles exist which establish the efficacy of vacuum therapy discovered in the 1980s. Examples of such prior art articles, each of which discusses the use of application of vacuum to a wound to promote healing, are as follows: “Vacuum therapy in the treatment of acute suppurative diseases of soft tissues and suppurative wounds”, Davydov, et al., Vestn, Khir., Sept. 1988 (“The September 1988 article”); “Pathenogenic mechanism of the effect of vacuum therapy on the course of the wound process”, Davydov, et al. Khirurigiia, June 1990 (“the June 1990 article”); and “Vacuum therapy in the treatment of suppurative lactation mastitis”, Davydov, et al. Vestn. Khir., November 1986 (“the November 1986 article”). The Russian articles distinguish wound drainage from use of vacuum therapy for healing. The Russian authors report that vacuum therapy resulted in faster cleansing of the wound and more rapid detoxification than with the traditional incision-drainage method. The November 1986 Russian article describes the vacuum therapy techniques as a reduction of 0.8-1atmosphere for 20 minutes at the time of surgery, and subsequent 1.5 to 3 hour treatments at a reduced pressure of 0.1 to 0.15 from atmosphere, twice daily. These Russian articles teach the use of negative pressure to effect healing. The articles describe using several sessions per day, each lasting up to one hour, with a vacuum of 76 -114 mmHg. The Russian articles teach using this vacuum method to decrease the number of microbes in the wound. The June 1990 Russian article teaches that this vacuum therapy provides a significant antibacterial effect. The article describes the stepped up inflow of blood to the zone around the wound to lead to an increase in the number of leukocytes reaching the focus of inflammation. Subsequent articles and patents further develop the benefits obtained with vacuum therapy. The prior art, therefore, teaches the benefit and value of a vacuum bandage.
A vacuum bandage is a bandage having a cover which seals about the outer perimeter of the wound and under which a vacuum is established to act on the wound surface. This vacuum applied to the wound surface causes healing of chronic wounds. Typically, suction tubes are provided for drawing away exudate from the wound, and this suction may be used to create the vacuum under the cover. If the cover is a flexible cover, which is typically more comfortable for the patient, some sort of porous packing may be provided under the cover to provide the space in which the vacuum is formed.
It would be desirable to incorporate in such a bandage a system configured to irrigate the wound surface and to withdraw the irrigation fluids without removal of the bandage. Accordingly, a wound care bandage is provided for use with a vacuum source, the bandage comprising a wound dressing member to be placed in contact with the wound surface. The vacuum source may be any source of vacuum including a vacuum pump and collection canister arrangement to which the bandage is coupled by a tube set. The dressing member either has an access port coupled to it or it is associated with an access port, the port being connected to the vacuum source. The dressing member, which illustratively is a relatively thin and flexible member, has a wound contacting surface and an opposite surface, and a plurality of channels or space providing passageways coupled to the access port to provide communication with areas of the wound surface. The wound contacting surface of the member illustratively includes spacers contacting the wound to define a suction space between the member and the wound surface. The member includes suction holes which communicate with the suction space formed by the spacers. The bandage includes passageways between the port and the suction holes. In some embodiments of the invention, the passageways are provided by a plurality of channels formed in the opposite surface and a cover positioned over the channels.
In some embodiments, the spacers and suction space are defined by a plurality of channels formed in the wound contacting surface. Each of the channels formed in the wound contacting surface opens toward the wound surface and includes side edges contacting the wound.
In some embodiments of the invention, the dressing member has such a plurality of channels formed in patterns on both of the wound contacting surface and the opposite surface and the plurality of holes provide communication between the channels on both surfaces. In some embodiments, the channel patterns on the both surfaces are congruent or superimposed with both patterns radiating outwardly from the port and with the holes spaced radially along the channels.
In some embodiments, the dressing member is made from a material which is to be trimmed conformingly to fit the wound. In some embodiments, the dressing member is relatively transparent such that the condition of the wound surface can be observed through the wound member.
There is provided, therefore, a dressing for a wound, the dressing comprising a relatively thin flexible member which can be trimmed conformingly to fit the wound surface. A suction and irrigation port is associated with the dressing member, and a plurality of channels or passageways is formed in the member leading away from the port to provide communication between the port and areas of the wound surface. The dressing member is provided with a plurality of through holes in communication with the channels. A packing may be placed over the flexible member and a sealing film may be placed over the packing to seal around the perimeter of the wound to provide an enclosed space above the member in which a vacuum is formed by suction on the port. Irrigation fluid may be introduced to the port to impinge upon the wound surface and this fluid and wound exudate is removed from the space between the wound and the bandage member by suction applied to the port. It will be appreciated that the vacuum therapy and the irrigation therapy may take place without removal of the bandage. The illustrative member with the downwardly opening channels or spacers on the wound contacting surfaces provides a suction space which will uniformly apply the vacuum and the irrigation to the surface of the wound bed.
The covered channels on the opposite surface and the holes through the member further contribute to the ability to uniformly apply the vacuum therapy and irrigation fluid to the wound surface. A relatively large portion of the wound surface will be exposed to the vacuum therapy and irrigation using the illustrative bandage member. A large number of redundant passageways are provided for communicating from the access port directly to the wound surface. While some of the passageways may become blocked by exudate particles from the wound surface, other passageways will remain open for suction and irrigation.
The illustrative bandage, therefore, provides a relatively thin, flexible, comfortable bandage member which can be trimmed conformingly to fit into a wound bed and apply vacuum therapy and irrigation uniformly to the wound surface. The illustrative covered channel passageways on the opposite (upper or outer) surface provide a multitude of clearly defined passageways leading from the access port to the through holes leading directly into the suction space under the member.
Features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.